,
whether he was there consenting to the murder, or whether he was there
as a spectator only.

One word more on this presence, called constructive presence. What aid
is to be rendered? Where is the line to be drawn, between acting, and
omitting to act? Suppose he had been in the house, suppose he had
followed the perpetrator to the chamber, what could he have done? This
was to be a murder by stealth; it was to be a secret assassination. It
was not their purpose to have an open combat; they were to approach
their victim unawares, and silently give the fatal blow. But if he had
been in the chamber, no one can doubt that he would have been an
abettor; because of his presence, and ability to render services, if
needed. What service could he have rendered, if there? Could he have
helped him to fly? Could he have aided the silence of his movements?
Could he have facilitated his retreat, on the first alarm? Surely, this
was a case where there was more of safety in going alone than with
another; where company would only embarrass. Richard Crowninshield would
prefer to go alone. He knew his errand too well. His nerves needed no
collateral support. He was not the man to take with him a trembling
companion. He would prefer to have his aid at a distance. He would not
wish to be encumbered by his presence. He would prefer to have him out
of the house. He would prefer that he should be in Brown Street. But
whether in the chamber, in the house, in the garden, or in the street,
whatsoever is aiding in _actual presence_ is aiding in _constructive
presence_; any thing that is aid in one case is aid in the other.[5]

If, then, the aid be anywhere, so as to embolden the perpetrator, to
afford him hope or confidence in his enterprise, it is the same as
though the person stood at his elbow with his sword drawn. His being
there ready to act, with the power to act, is what makes him an abettor.

Here Mr. Webster referred to the cases of Kelly, of Hyde, and
others, cited by counsel for the defendant, and showed that they
did not militate with the doctrine for which he contended. The
difference is, in those cases there was open violence; this was a
case of secret assassination. The aid must meet the occasion. Here
no _acting_ was necessary, but watching, concealment of escape,
management.

What are the _facts_ in relation to this presence? Frank Knapp is proved
to have been a conspirator, proved to have kno